SMART TEXTILES LAB – PRINTED ELECTRONICS FOR SMART TEXTILES

REFRAME THE FAMILIAR

Sometimes we need to stretch our imagination and think outside the existing frameworks that we, together, have created for ourselves. Please take your phone out of your pocket for a moment and have a good look at it. You have probably looked at it a million times alreadybut try to see it as if you have never seen it before. It has a rigid rectangular shape, a smooth and shiny surface, maybe with a few scratches here and there. Isn’t it strange to think how closely involved you can be with this relatively cold device. While holding it in your hand, imagine this phone becoming much more lightweight and pliable, with a texture that invites you to touch it. Suddenly, you are no longer looking at a rigid screen, but at a soft piece of fabric. Through seamlessly embedded electronics it is able to sense things and respond to it.

BUILDING ON THE INTIMACY OF CLOTHING

Now, consider you are wearing this fabric. Imagine how it could enhance your embodied experience, or the way you perceive the world. And how all this could ultimately enable new relationships with the things we wear. Over the past eight years of working in the field of wearable technology, I have been exploring how smart textiles can be of benefit to specific people and in specific situations. And at the same time, how wearables can open up alternatives for the problems in today’s fashion industry, caused by over-consumption and the undervaluation of resources (both materials and humans). Right now, from my position at the Holst Centre, I am trying to bring smart textiles and clothing to life with the help of printed electronics.

PRINTED ELECTRONICS: HOW DOES IT WORK?

Holst Centre is a Dutch research centre specialized in the development of printed electronics. Unlike regular electronics, these circuits are thin, lightweight, flexible and even stretchable. They enable all kinds of products and materials to become interactive. The material qualities of these printed electronics are particularly suitable for integration in textiles. To create these circuits, we use conductive inks made of materials like silver and carbon that are printed on stretchable substrates, such as TPU films (Thermoplastic Polyurethane) (figure 1). Special inks with a high degree of elasticity are developed for this purpose, such as DuPont’s IntexarTM. We also develop certain designs, like the meander-shaped tracks that mechanically increase the stretchability.

DESIGNING WITH PRINTED ELECTRONICS

One of the biggest advantages of printed electronics is that you can think of it as a trim, which can be easily integrated in the garment using the well-known assembly procedure of heat-bonding. Moreover, from a design perspective, you have a lot of freedom to give a particular shape and expression to the circuitry. Oftentimes, instead of hiding it on the inside of the garment, we turn it into a unique visible feature. When placing these electronics on the body, we take freedom of movement and comfort into account. Typically, we encapsulate the electronics with TPU bonding films, which we get supplied by companies like Framis Italia.

We work with companies ranging from fashion brands, garment manufacturers, start-ups like Niraxx and Bambi Medical, andlarge companies like Philips. One of our main focus areas is to enhance human vitality, by supporting people at work, during sports or by enhancing their overall well-being. The fact that our clothes can communicate directly and discretely with our body through touch is something we see great potential in. Together with Maxime Dassen (Industrial Designer at Tue) we created Mysa, a sweater that reduces stress by guiding the wearer through breathing exercises using subtle vibrations along the spine programmed in a calming rhythm.

DURABILITY AND SUSTAINABILITY

Of course, we are also facing challenges still. We characterize the printed and bonded materials extensively. Besides this, we perform tensile and washing tests in order to ensure their functioning over time and especially in view of the heavy wear and tear they must be able to withstand. And while optimizing our materials, we also take into account the end of life of products. Together with designer Marina Toeters of by-wire.net we researched how printed electronics can be delaminated from textiles in order to prepare for recycling.